Networking - VPC Flashcards
WW.XX.YY.ZZ/32 is how many IPs
one IP
0.0.0.0/0 is how many IPs?
all IPs
The subnet masks defines how many ___ can change in the IP?
bits
How do you calculate how many IP’s can exist from the subnet mask?
/31 allows for 2 IP = 2^1
How many VPC’s can attach to an internet Gateway?
Only one
What does enableDnsSupport: (= DNS Resolution setting) do?
Helps decide if DNS resolution is supported for theVPC
• IfTrue,queriestheAWSDNSserverat169.254.169.253
Explain • enableDnsHostname: (= DNS Hostname setting)
- False by default for newly created VPC,True by default for Default VPC
- Won’t do anything unless enableDnsSupport=true
- IfTrue,Assign public hostname to EC2 instance if it has a public
What’s a Network ACL?
• NACL are like a firewall which control traffic from and to subnet
How many NACL’s per subnet?
One
Define NACL rules? What’s takes precedence?
Rules have a number (1-32766) and higher precedence with a lower number
NACL are a great way of blocking a specific __ at the ___ level
IP, subnet
What does VPC endpoints allow you to do?
Endpoints allow you to connect to AWS Services using a private network instead of the public www network
VPC Endpoints Interface does what?
provisions an ENI (private IP address) as an entry point (must attach security group) – most AWS services
VPC Endpoints Gateway does what?
provisions a target and must be used in a route table – S3 and DynamoDB
What’s the point of flow logs?
- Capture information about IP traffic going into your interfaces: • VPC Flow Logs
- Subnet Flow Logs
- Elastic Network Interface Flow Logs
